Trajectory Modelling of Transition Regime Using Blade Element Method for Different eVTOL Aircraft Configurations

Abstract

With the rising popularity of Electric Vertical Take Off and Landing (eVTOL) aircraft, there is a proliferation of numerous works on the different eVTOL designs with configurations such as vectored thrust, lift + cruise and multicopter. However, there are limited published studies focusing on the characteristics of transition flight for different eVTOL aircraft configurations. This paper investigates the generation and derivation of the complete eVTOL aircraft transition model based on both the transitional flight trajectory and power requirements. Different modelling modules using the eVTOL aircraft flight trajectory are developed and integrated within MATLAB, including the use of Blade Element Momentum Theory in the power required module. In addition, a generalized trim module determines the balanced forces and moments acting on the eVTOL aircraft. In the kinematic module, the trajectory model accounts for the dynamic and transient conditions during the transition phase. These modules enables the study of the full transition regime for any eVTOL aircraft and is applicable for different eVTOL configurations, including tiltrotors. The estimation of the transitional power required for these eVTOL aircraft for given a transition trajectory, allows for proper motor and energy battery sizing. This research benefits the aircraft designers and the eVTOL industry to deepen the understanding of the transition regime for eVTOL aircraft.